Skip to main content

Full text of "The Morphology And Evolution Of The Apes And Man"

See other formats

THE SKELETON AND TEETH              129
Although the crests increase as age advances it is not
an absolute rule that the older animal has alwavs the
larger crest.
The lambdoid crest varies in size, but the infra-temporal crest is small.
The zygoma is strong and massive, and its malar and temporal parts are of equal depth; but in the Chimpanzee it is slender, and its "ernporal part is narrower than its malar component. The temporal fossa is wide, its depth being further augmented by the channelling of the alisphenoid. The latter does not unite with the parietal bone at the pterion, but is excluded from it by the articulation of the frontal with the squamosal. In this the
skull agrees with* that of the Chimpanzee, but  differs from those of Man and the Asiatic Simiidse.
The spheno-maxillary fissure is narrow, as in the Chimpanzee, but is not so curved. The external auditory meatus is the same size as in the Chimpanzee, so it is smaller relatively to the size of the skull in the
Norma Basalis.—The bony palate differs in its genera! proportions from that in the Chimpanzee; its length predominates over its width, whereas the reverse is the case in the latter.
The premaxillary part of the palate is relatively longer, und the anterior palatine foramina are relatively smaller in the Chimpanzee. The absolute palatal area in the Gorilla greatly exceeds that in the Chimpanzee; thus Keith (100) found that the average area in seven adult male Gorillas was 7,200 mm., in fifteen adult male Chimpanzees it was 4,580 mm., in seven adult female Gorillas it was 5,600 mm., and in eleven adult female 9